Method for sharing network information and a router apparatus

Abstract

A highly-expandable router configuration technology which flexibly meets the need to increase lines as a network grows. A network information sharing unit is provided in a route calculation unit of each router in a clustered router. The network information sharing unit receives an update notification of network information collected by routing protocol units and sends this update information to all other routers in the clustered router as a network information notification packet. The network information sharing units in the receiving router notifies the routing protocol units of the contents of the received updated information. The routing protocol unit updates the network information thereof based on the notified contents, thereby allowing the network information obtained from all routers outside the clustered router to be shared and the clustered router to be recognized externally as a single router.

What is claimed is:  
     
         1 . A network information sharing method using routers connecting networks to which communication terminals are connected, said network information sharing method comprising the steps of: 
 forming network information with a network information notification packet which includes a type of a routing protocol;    transferring said network information notification packet among routing protocol programs of one or more other routers; and    generating a routing table based on said network information included in said network information notification packet using said routing protocol program, said routing table being used to determine a destination of a packet to be transferred among said communication terminals.    
     
     
         2 . A network information sharing method using routers which have a plurality of route calculation units, one of said plurality of route calculation units being in active state with the rest in backup state, said network information sharing method comprising the steps of: 
 forming network information with a network information notification packet which includes a type of a routing protocol;    transferring said network information notification packet to routing protocol programs each operating in said route calculation units in backup state with the use of the routing protocol program operating in said route calculation unit in active state; and    when said route calculation unit in active state fails, sending or receiving the network information to or from other routers with the use of said routing protocol program in one of said route calculation units in backup state based on said transferred network information.    
     
     
         3 . A network information sharing method using a router in which a plurality of routing protocol programs operate, each of said plurality of routing protocol programs executing a different routing protocol, said network information sharing method comprising the steps of: 
 forming network information with a network information notification packet which includes a type of the routing protocol;    transferring said network information among routing protocol programs of one or more other routers, said network information being collected based on the routing protocol corresponding to each of said routing protocol programs; and    receiving said network information collected based on the other routing protocols and sending said network information to an external router.    
     
     
         4 . A network information sharing method using a plurality of routers connecting networks to which communication terminals are connected, said network information sharing method comprising the steps of: 
 forming network information with a network information notification packet which includes a type of a routing protocol;    transferring said network information notification packet among routing programs of said plurality of routers, said network information notification packet including said network information collected by the routing protocol of the routing protocol programs provided in each of said plurality of routers; and    generating a routing table based on said network information using said routing protocol program, said routing table being used to decide a destination of a packet to be transferred among said communication terminals.    
     
     
         5 . A router connecting networks to which communication terminals are connected and which allows network information  16  to be shared, said router comprising: 
 means for forming the network information with a network information notification packet which includes a type of a routing protocol;  
 means for transferring said network information notification packet among routing protocol programs of one or more other routers; and  
 means for generating a routing table based on said network information included in said network information notification packet using said routing protocol program, said routing table being used to decide a destination of a packet to be transferred among said communication terminals.  
 
     
     
         6 . A clustered router comprising a plurality of routers connecting networks to which communication terminals are connected, each of said plurality of routers comprising: 
 means for forming the network information with a network information notification packet which includes a type of a routing protocol;    means for transferring said network information notification packet among routing programs of said plurality of routers, said network information notification packet including said network information collected by the routing protocol of the routing protocol program provided in each of said plurality of routers; and    means for generating a routing table based on said network information using said routing protocol program, said routing table being used to decide a destination of a packet to be transferred among said communication terminals.    
     
     
         7 . A router which has a plurality of route calculation units and which allows network information to be shared, one of said plurality of route calculation units being in active state with the rest in backup state, said router comprising: 
 means for forming the network information with a network information notification packet which includes a type of a routing protocol;    means for transferring said network information notification packet to routing protocol programs each operating in said route calculation units in backup state with the use of the routing protocol program operating in said route calculation unit in active state; and    means for sending or receiving the network information to or from other routers with the use of said routing protocol program in one of said route calculation units in backup state based on said transferred network information when said route calculation unit in active state fails.    
     
     
         8 . A router in which a plurality of routing protocol programs operate and which allows network information to be shared, each of said plurality of routing protocol programs executing a different routing protocol, said router comprising: 
 means for forming the network information with a network information notification packet which includes a type of the routing protocol;    means for transferring said network information among routing protocol programs of one or more other routers, said network information being collected based on the routing protocol corresponding to each of said routing protocol programs; and    means for receiving said network information collected based on the other routing protocols and sending said network information to an external router.